After discussing other matters publicly, the board voted to meet in closed session. Afterward, several board members and its director, Avery Aisenstark, a city employee, would not answer questions about what was discussed.

"We're not authorized to discuss the reason for or topic of the closed meeting — let alone why something was or was not discussed," Aisenstark said in an email.

The board launched an inquiry last month, citing concerns about the distribution of free tickets to the mayor's family and staff. The Baltimore Sun reported that Rawlings-Blake's office received hundreds of tickets each year to events at the city-owned arena. The mayor, accompanied by relatives and top aides, used the free tickets to attend several sold-out concerts, including shows featuring Rihanna and Jay-Z.

In a letter, Rawlings-Blake's law office told board members it couldn't find the current contract it has argued allows her to accept the free tickets, but could find an older version of the agreement with the arena that permits the practice. The 1988 agreement, signed during Mayor Kurt L. Schmoke's administration, also provided for other free ticket provisions, including requiring the management to honor 30 "lifetime gold passes" and 33 transferable passes to the arena. The contract said the mayor would select recipients if the passes were transferred or expired.

Rawlings-Blake's spokesman, Ryan O'Doherty, has said that the mayor has made ethics a top priority of her administration and "welcomes any review of this long-standing policy that goes back several decades and administrations." He also noted that the mayor "provides hundreds of complimentary tickets from the city-owned facility to hard-working employees, school students, elected officials, youth leagues, community groups, and charitable organizations."